The present invention relates to a manually-guided, portable suction device/blower.
With manually-guided, portable suction devices/blowers, an air stream is produced by means of a motor-driven blower unit. By means of a suction or vacuum tube that is connected, for example, on the suction side of the suction device/blower, dust, leaves or the like can be sucked up from the ground and blown into a collection bag via a blower tube that is disposed on the discharge side.
Embodiments are also known where an underpressure device, for example in the form of a venturi device, which is actuated by the air stream, is disposed in the blower tube. In this connection, a suction tube opens out into the venturi device. Matter can be drawn in through the suction tube and the venturi device and can be conveyed further via the blower tube to the collection bag, without having to pass the blower unit that drives the air stream. Such arrangements are used in particular to suck up larger or harder or sensitive matter, especially for harvesting nuts or the like.
The aforementioned suction devices/blowers are carried, for example, on the back and are manually guided. The housing of the blower unit, and in particular the blower tube, are made of plastic, which acts as an electrical insulator relative to the drive motor.
At an appropriate blower power, a relatively high flow velocity forms in the blower tube. At appropriate atmospheric conditions, and when sucking up atmospheric air that is loaded with dirt or dust particles, this high velocity can lead to electrostatic charges, especially due to friction between the particles and the fanwheel blower, the blower housing, and with the wall of the blower tube. The electrically charged particles carried along in the air stream have an electrical potential difference relative to the surrounding components. The particles themselves, and in particular components of the suction device/blower, develop an electrical potential relative to one another and also relative to the environment. When the suction device/blower, and in particular the collection bag, are contacted, an electrostatic discharge that is uncomfortable for the operator can occur.
It is therefore an object of the present invention to provide a suction device/blower of the aforementioned general type with which the formation of an electrostatic charge is at least largely avoided.